Design and Industrialisation of Solidly-Mounted BAW filters

This paper discusses the design of high-Q bulk-acoustic-wave filters that are optimised for integration in to front-end-modules (FEM) for 2G/3G cellular applications. In addition, the industrialisation aspects of BAW filters are presented. A novel low-cost process was developed based on standard IC processing which uses a solidly mounted reflector stack of dielectric materials. Experimental results are shown of filters operating at 1.9 GHz. The loss mechanisms that occur in BAW filters which are produced in high-volume are analysed